The present invention relates to a beam antenna direction measuring method and a device for detecting the direction(azimuthal and elevation angles) of an antenna by detecting a geomagnetic field. Further, the invention relates to a beam antenna direction controller capable of turning the antenna in a predetermined direction and a controlling method thereof.
Conventionally known antenna direction(azimuthal and elevation angles) measuring methods and controllers make use of mechanical systems, wherein, for example, by utilizing the fact that resistance values are changed by a variable resistor(volume), etc., attached to the rotational part of the antenna in accordance with its rotational angle, the beam direction of the antenna is determined from the changes of the resistance values.
In a device of this type, generally the beam direction of the antenna must be predetermined by a magnetic compass, etc., and the directions of an indoor antenna controller and a rooftop antenna must be adjusted. This makes it necessary to align a bearing stylus indicating the direction of the indoor antenna controller with the direction of the rooftop antenna, and then to fix the rooftop antenna on the rotor of the antenna by bolts.
In the conventional antenna controller described above, as it is necessary to at least align the direction of the rooftop antenna beam with the bearing stylus direction of the indoor antenna controller, the following problems occur. The beam direction of the rooftop antenna must be set in the same direction as the bearing stylus of the indoor antenna controller. Thus, it is necessary to determine the beam direction of the antenna by use of a magnetic compass, etc.
In such a device, as the rotation of the antenna and that of the controller bearing stylus must be accurately aligned during manufacturing, assembling adjustment work is made complicated in the manufacturing process. Also, when the direction of the rooftop antenna beam is shifted due to strong winds, etc., it is necessary to align the direction of the rooftop antenna with the bearing stylus of the indoor antenna controller.
Further, in the conventional system, as the fact that the resistance values are changed by the variable resistor(volume), etc., attached to the rotational part of the antenna in accordance with its rotational angle, there is a problem of durability of the device, which is reduced due to frictions of the contact part, i.e., the mechanical part.
Further, because of the structural reasons described above, it is impossible for the antenna controller to rotate in the same direction several times, and thus most of the currently sold devices are allowed only one direction rotation. When wishing to rotate the antenna direction to the right only by 10.degree. from the current direction by means of such an antenna controller, if the current antenna is rotated in a right direction up to the limit, it must be reversely rotated to the left by 350.degree..
Further, in the conventional product, in the case where the beam antenna is attached to moving bodies such as a motor vehicle, a ship and the like, when the traveling direction of the moving body is changed, the direction of the beam antenna attached thereto is also changed, it is necessary to know which direction the moving body is facing in order to know the real direction of the antenna beam, and thus a very expensive device is needed and further, its data processing is very complicated.